1 /** 2  * Server,NIO本质是非阻塞。 Selector SelectionKey ServerSocketChannel SocketChannel 3  */ 4 public class MyServerSocketChannel { 5     public static void main(String[] args) { 6         Selector sel = null ; 7         // 8         try { 9             sel = Selector.open();                                            //开启挑选器10             ServerSocketChannel ssc = ServerSocketChannel.open();            //开启服务器SocketChannel11             InetSocketAddress addr = new InetSocketAddress("0.0.0.0", 8888);12             ssc.bind(addr);13             ssc.configureBlocking(false);                                    //配置非阻塞14             ssc.register(sel, SelectionKey.OP_ACCEPT);                        //***** 在挑选器中注册ssc通道 *****15         } catch (Exception e) {16             e.printStackTrace();17         }18         19         SocketChannel sc0 = null;20         ByteBuffer buf = null;21         // CharBuffer cbuf = CharBuffer.allocate(1024);22         while (true) {23             // 开始挑选24             try {25                 sel.select();                                                //开始挑选26             } catch (Exception e) {27                 e.printStackTrace();28             }29             // 处理发生的事件30             Set
     
       keys = sel.selectedKeys();                    //获得selectedKey集合31             for (SelectionKey key : keys) {32                 try {33                     // 是否是accept事件34                     if (key.isAcceptable()) {35                         // 得到服务器通道36                         ServerSocketChannel ssc0 = (ServerSocketChannel) key.channel();//ssc0和ssc是同一个服务器通道，只是不同的引用37                         // 接受客户端连接，返回SocketChannel38                         sc0 = ssc0.accept();39                         System.out.println(getClientInfo(sc0.socket()) + " : 上线了!" );40                         // 注册非阻塞41                         sc0.configureBlocking(false);42                         // 在挑选器中注册新产生的SocketChannel43                         sc0.register(sel, SelectionKey.OP_READ | SelectionKey.OP_WRITE | SelectionKey.OP_CONNECT);44                         //45                     }46                     // 可以读取数据了。47                     if (key.isReadable()) {48                         // 得到SocketChannel49                         sc0 = (SocketChannel) key.channel();50                         ByteArrayOutputStream baos = new ByteArrayOutputStream();51 52                         //53                         buf = ByteBuffer.allocate(1024);54                         // 读取客户端发送的数据55                         while (sc0.read(buf) != 0) {56                             buf.flip();57                             baos.write(buf.array(), 0, buf.limit());58                             buf.clear();                        //重置buf59                         }60                         // 构造缓冲区，写回去client.61                         String str = "hello : " + new String(baos.toByteArray());62                         // 输出内容63                         System.out.println(getClientInfo(sc0.socket()) + str);64                         65                         //回传信息66                         buf = ByteBuffer.allocate(str.getBytes().length);67                         buf.put(str.getBytes());68                         buf.flip();69                         sc0.write(buf);70                         buf.clear();71                     }72                 } catch (Exception e) {73                     //从selector注销通道74                     key.cancel();75                     //76                     if(key.channel() instanceof SocketChannel){77                         Socket s = ((SocketChannel)key.channel()).socket();78                         System.out.println(getClientInfo(s) + " : 下线了！");79                     }80                 }81             }82             keys.clear();83         }84     }85 86     /**87      * 获得客户端信息88      */89     private static String getClientInfo(Socket socket) {90         InetSocketAddress addr = (InetSocketAddress) socket.getRemoteSocketAddress();91         String ip = addr.getAddress().getHostAddress();92         String port = addr.getPort() + "";93         return "[" + ip + ":" + port + "] ";94     }95 }
     

2、客户端

1 /** 2  * 客户端 3  */ 4 public class MyClientSocketChannel { 5     public static void main(String[] args) throws Exception { 6         Selector sel = Selector.open();                //挑选器 7         SocketChannel sc = SocketChannel.open();    //开启通道 8         InetSocketAddress addr = new InetSocketAddress("localhost", 8888);//服务器地址 9         sc.connect(addr);                            //连接10         11         sc.configureBlocking(false);                //*****非阻塞模式12         sc.register(sel, SelectionKey.OP_READ);        //注册read事件13         14         new Sender(sc).start();                        //开启线程发送消息15         16         //17         ByteBuffer buf = ByteBuffer.allocate(1024);18         //开始挑选19         while(true){20             sel.select();21             ByteArrayOutputStream baos = new ByteArrayOutputStream();22             while(sc.read(buf) != 0){23                 buf.flip();24                 baos.write(buf.array(),0,buf.limit());25                 buf.clear();26             }27             String str = new String(baos.toByteArray());28             System.out.println(str);29         }30     }31 }

3、多线程分支读取数据的输入

1 /** 2  * 发送器线程 3  */ 4 public class Sender extends Thread{ 5     private SocketChannel sc ; 6     public Sender(SocketChannel sc){ 7         this.sc = sc ; 8     } 9     public void run() {10         try {11             //读取console内容，写入到sc12             BufferedReader br = new BufferedReader(13                     new InputStreamReader(System.in));14             String line = null ;15             ByteBuffer buf = null ;16             while((line = br.readLine()) != null){17                 buf = ByteBuffer.allocate(1024);18                 buf.put(line.getBytes());19                 buf.flip();20                 sc.write(buf);21                 buf.clear();22             }23         } catch (Exception e) {24             e.printStackTrace();25         }26     }27 }

 2、

1 public class MyServer { 2     public static void main(String[] args) { 3     //创建挑选器 4         try { 5             Selector sel = Selector.open(); 6         //获取服务器通道 7             ServerSocketChannel ssc = ServerSocketChannel.open(); 8         //设置非阻塞模式 9             ssc.configureBlocking(false);10         //绑定地址11             ssc.socket().bind(new InetSocketAddress("localhost", 8888));12             13         //在挑选器中注册通道，指定感兴趣事件14             ssc.register(sel, SelectionKey.OP_ACCEPT);15         16             while(true){17                 //不断地挑选18                 sel.select();19                 //被挑选出的key的集合20                 Set
     
       keys = sel.selectedKeys();21                 Iterator
      
        it = keys.iterator();22                 23                 while(it.hasNext()){24                     SelectionKey key = it.next();25                     if(key.isAcceptable()){26                         SocketChannel sc = ssc.accept();27                         System.out.println("有人连进来了");28                         sc.configureBlocking(false);29                         sc.register(sel, SelectionKey.OP_READ|SelectionKey.OP_WRITE);30                         System.out.println("有人注册了");31                     }32                     if(key.isReadable()){33                         SocketChannel sc = (SocketChannel) key.channel();34                         System.out.println(readStrFromChannel(sc));35                     }36                     if(key.isWritable()){37                         ByteBuffer buf = ByteBuffer.allocate(1024);38                         buf.put("hello world".getBytes());39                         buf.flip();40                         SocketChannel sc = (SocketChannel) key.channel();41                         sc.write(buf);42                         key.cancel();//取消连接43                     }44                     it.remove();45                 }46                 //keys.clear();47             }48         } catch (Exception e) {49             50             51         }52     }53     private static String readStrFromChannel(SocketChannel sc) {54         ByteArrayOutputStream bos = new ByteArrayOutputStream();55         ByteBuffer buffer = ByteBuffer.allocate(1024);56         try {57             while(sc.read(buffer)>0){58                 buffer.flip();59                 bos.write(buffer.array(), 0, buffer.limit());60             }61             return new String(bos.toByteArray());62         } catch (IOException e) {63             e.printStackTrace();64         }65         return null;66     }67 }
      
     

1 public class MyClient { 2  3     public static void main(String[] args) { 4         try { 5             Selector sel = Selector.open(); 6             SocketChannel sc = SocketChannel.open(); 7             sc.configureBlocking(false); 8             SelectionKey key = sc.register(sel, SelectionKey.OP_CONNECT | SelectionKey.OP_READ | SelectionKey.OP_WRITE); 9             sc.connect(new InetSocketAddress("localhost", 8888));10             int i=0;11             while (true) {12                 sel.select();13                 // 挑选器中最多只有一个对象14                 if (sel.selectedKeys().isEmpty()) {15                     continue;16                 }17                 if (key.isConnectable()) {18                     sc.finishConnect();19                 }20                 if (key.isReadable()) {21                     String src=(readStrFromChannel(sc));22                     if(src !=null){23                         System.out.println(src);24                     }25                 }26                 if(key.isWritable()){27                     ByteBuffer buffer = ByteBuffer.allocate(11);28                     buffer.put("hello wokd".getBytes());29                     buffer.flip();//重新定位指针，用于写30                     sc.write(buffer);31                 }32                 i++;33             }34 35         } catch (Exception e) {36             e.printStackTrace();37         }38     }39 40     private static String readStrFromChannel(SocketChannel sc) {41         ByteArrayOutputStream bos = new ByteArrayOutputStream();42         ByteBuffer buffer = ByteBuffer.allocate(20);43         try {44             if(sc.read(buffer)>0){45                 buffer.flip();46                 bos.write(buffer.array(), 0, buffer.limit());47                 //buffer.clear();48             }49             return new String(bos.toByteArray());50         } catch (IOException e) {51             e.printStackTrace();52         }53         return null;54     }55 56 }